JP2020035709A - Battery pack cooling structure - Google Patents

Abstract

To configure, with the minimum number of components, a refrigerant jacket of an upper stage battery case of a two-story battery case.SOLUTION: A recessed portion 42b recessed upward is formed in a case lower wall 42a of a second battery case 32 that is superposed on an upper side of a first battery case 31, a battery 45 is mounted on a top surface of the recessed portion 42b, and a refrigerant jacket 47 is formed between a bottom surface of the recessed portion 42b and the top surface of the first battery case 31 connected to the bottom surface. Thus, not only a refrigerant jacket 47 can be configured using existing first and second battery cases 31, 32 without adding special members, but also, even if a refrigerant leaks from the refrigerant jacket 47, there is no risk that the refrigerant enters into the inside of the first battery case 31 or the second battery case 32.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery pack cooling structure including a battery pack in which a second battery case is superimposed on a first battery case, and a refrigerant jacket through which a refrigerant flows is formed on a lower surface of the second battery case.

  A plate-shaped coolant line (refrigerant jacket) having a plurality of coolant passages formed inside is brought into contact with the bottom surface of the battery, and this coolant line is fixed to the bottom surface of the battery by a clamp element with the heat insulation element interposed therebetween. A cooling device for a vehicle battery is known from Patent Document 1 below.

  Further, a battery assembly cooling structure for a vehicle in which a lower surface of a battery case for storing a battery is cooled by a traveling wind of the vehicle and a water jacket is provided on an upper surface and a rear surface of the battery case, which is hard to contact with the traveling wind, is disclosed in Patent Document 2 below. Is known.

Japanese Patent No. 5847815 JP 2011-6025 A

  By the way, when a battery pack of a hybrid vehicle includes a two-story battery case stacked vertically, it is necessary to provide a coolant jacket not only on the battery case on the first floor but also on the battery case on the second floor. However, there is a problem that the number of parts increases.

  The present invention has been made in view of the above circumstances, and has as its object to configure a refrigerant jacket of an upper battery case of a two-story battery case with a minimum number of parts.

  To achieve the above object, according to the invention described in claim 1, a battery pack is provided in which a second battery case is superimposed on a first battery case, and a refrigerant is provided on a lower surface of the second battery case. A cooling structure for a battery pack having a flowing refrigerant jacket, wherein a concave portion that is depressed upward is formed in a lower wall of the case of the second battery case, a battery is placed on an upper surface of the concave portion, and a lower surface of the concave portion is provided. A cooling structure for a battery pack, wherein the refrigerant jacket is formed between the battery pack and the upper surface of the first battery case coupled thereto.

  According to the second aspect of the invention, in addition to the configuration of the first aspect, the case side wall of the first battery case includes a refrigerant supply passage for supplying a refrigerant to the refrigerant jacket and a refrigerant supply passage. A cooling structure for a battery pack is proposed in which a refrigerant discharge passage for discharging the refrigerant is formed.

  According to the third aspect of the present invention, in addition to the configuration of the first or second aspect, the case upper wall of the first battery case is located outside the seal member surrounding the outer periphery of the refrigerant jacket. There is proposed a cooling structure for a battery pack, characterized in that the cooling structure is inclined downward toward the battery pack.

  According to a fourth aspect of the present invention, in addition to the configuration of the second aspect, the third battery includes one or more third battery cases superimposed on the second battery case. On the lower surface of the case, another refrigerant jacket is formed between the lower surface of the battery case and the upper surface of the lower battery case, and on the case side wall of the third battery case, the refrigerant supply passage and the refrigerant discharge of the lower battery case overlap. A cooling structure for a battery pack is proposed in which a coolant supply passage and a coolant discharge passage are formed to communicate with the passages.

  According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect, the upper battery case has a larger flow path cross-sectional area of the refrigerant supply passage and the refrigerant discharge passage. A pack cooling structure is proposed.

  According to the invention described in claim 6, in addition to the configuration of claim 4, a cooling structure for a battery pack is proposed, wherein the capacity of the refrigerant jacket is larger in the upper battery case. .

  In addition, the left case side wall 33d and the right case side wall 33f of the embodiment correspond to the case side wall of the present invention, and the cooling water supply passage 33e and the cooling water discharge passage 33g of the embodiment correspond to the refrigerant supply passage and the refrigerant of the present invention, respectively. The cooling water supply passage 42e and the cooling water discharge passage 42f of the embodiment correspond to the refrigerant supply passage and the refrigerant discharge passage, respectively, and the battery module 45 of the embodiment corresponds to the battery of the invention. Correspondingly, the second water jacket 47 of the embodiment corresponds to the refrigerant jacket of the present invention, and the left case side wall 52a and the right case side wall 52b of the embodiment correspond to the case side wall of the present invention. The water supply passage 52c and the cooling water discharge passage 52d correspond to the refrigerant supply passage and the refrigerant discharge passage of the invention, respectively, and The third water jacket 54 corresponding to the other refrigerant jacket of the present invention.

  According to the configuration of the first aspect, the battery pack is provided with the second battery case superimposed on the first battery case, and the refrigerant jacket through which the refrigerant flows is formed on the lower surface of the second battery case. A concave portion which is concave upward is formed in a lower wall of the case of the second battery case, a battery is mounted on an upper surface of the concave portion, and a refrigerant jacket is provided between a lower surface of the concave portion and an upper surface of the first battery case coupled thereto. Is formed, the refrigerant jacket can be formed using the existing first battery case and the second battery case without adding a special member, and the refrigerant jacket is formed of the first battery case and the second battery case. Therefore, even if the refrigerant leaks from the refrigerant jacket, there is no possibility that the refrigerant may enter the inside of the first battery case or the second battery case.

  According to the configuration of the second aspect, the coolant supply passage for supplying the coolant to the coolant jacket and the coolant discharge passage for discharging the coolant from the coolant jacket are formed on the case side wall of the first battery case. (1) The number of components is reduced by eliminating the necessity of arranging a pipe through which refrigerant flows outside the battery case, and the number of components is reduced by using a common seal member for sealing the refrigerant jacket, the refrigerant supply passage, and the refrigerant discharge passage. Is further reduced.

  According to the third aspect of the invention, since the case upper wall of the first battery case is inclined downward and outward outside the seal member surrounding the outer periphery of the refrigerant jacket, the refrigerant should leak from the seal member. Even in this case, the leaked refrigerant is prevented from accumulating on the upper surface of the case upper wall of the first battery case.

  According to the configuration of claim 4, one or more third battery cases are superimposed on the upper side of the second battery case, and the lower surface of the third battery case has the upper surface of the battery case overlapping therebelow. Another coolant jacket is formed between the first battery case and the third battery case, and a coolant supply passage and a coolant discharge passage communicating with the coolant supply passage and the coolant discharge passage of the battery case overlapping therebelow are formed on the case side wall of the third battery case. Therefore, even when the battery cases are stacked in three or more stages, it is possible to efficiently cool the battery cases in each stage while minimizing the increase in the length of the refrigerant passage.

  Further, according to the configuration of the fifth aspect, as the upper battery case has a larger flow passage cross-sectional area of the refrigerant supply passage and the refrigerant discharge passage, the supply amount of the refrigerant to the upper refrigerant jacket where the refrigerant is difficult to reach is increased. By doing so, the cooling effect of the battery case in each stage can be made uniform.

  According to the configuration of claim 6, since the capacity of the refrigerant jacket is larger in the upper battery case, the supply amount of the refrigerant to the upper refrigerant jacket in which the refrigerant is difficult to reach is increased, so that the battery case of each stage is increased. The cooling effect of the case can be made uniform.

It is a vehicle body side view of a plug-in hybrid vehicle. (First Embodiment) FIG. 3 is an exploded perspective view of the battery pack. (First Embodiment) FIG. 3 is an enlarged view of a part of FIG. 1. (First Embodiment) FIG. 4 is a sectional view taken along line 4-4 of FIG. 3. (First Embodiment) FIG. 3 is a view in the direction of arrows in FIG. 2. (First Embodiment) FIG. 3 is a view in the direction of arrows in FIG. 2. (First Embodiment) It is a figure showing arrangement of the 1st water jacket and the 2nd water jacket. (First Embodiment) It is a figure showing composition of the 1st-3rd water jacket. (Second embodiment)

First embodiment

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. Note that the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction in this specification are defined with reference to an occupant seated in a driver's seat.

  As shown in FIG. 1, an electric motor 11 for driving front wheels, an engine 12 for driving a generator for charging a battery, and control of driving of the electric motor 11 are provided at the front of the vehicle body of the front-wheel drive plug-in hybrid vehicle. And a power drive unit 13 having an inverter to be mounted. A front seat 15 and a rear seat 16 are arranged on an upper surface of the floor panel 14, and a battery pack 17 for supplying power to the electric motor 11 is mounted on a lower surface of the floor panel 14 below the rear seat 16. An exhaust pipe 18 extends rearward from the engine 12, and a muffler 19 provided at an intermediate portion of the exhaust pipe 18 is disposed below the battery pack 17.

  As shown in FIG. 2, the battery pack 17 includes a lower first battery case 31 and an upper second battery case 32 superposed on the front upper portion of the first battery case 31. The first battery case 31 includes a first case main body 33 and a first cover 34, both of which are made of metal die-cast. The first cover 34 is connected to the upper surface opening of the first case main body 33. At the center of the first case body 33 in the vehicle width direction, a groove-shaped recess 33a having a semicircular cross section and extending in the front-rear direction is formed so as to be recessed upward, and the muffler 19 (FIG. Part) is accommodated.

  As shown in FIG. 3 to FIG. 5 and FIG. 7, the first case main body 33 includes a left case bottom wall 33b and a right case bottom wall 33c divided into right and left by a concave portion 33a, and a lower surface of the left case bottom wall 33b. The left first water jacket 36A is formed between the left case bottom wall 33b and the left cover member 35A by connecting the left cover member 35A, and the right cover member 35B on the lower surface of the right case bottom wall 33c is connected. A first right water jacket 36B is formed between the right case bottom wall 33c and the right lid member 35B.

  A cooling water supply port 36 a through which cooling water is supplied from a cooling water tank (not shown) is formed at the front end and the inner end (right end) of the first left water jacket 36 </ b> A in the vehicle width direction. A cooling water supply passage 33e for supplying the cooling water discharged from the left end of the left first water jacket 36A to the second battery case 32 is formed upward on the side wall 33d. A cooling water discharge port 36b for discharging cooling water to a cooling water tank (not shown) is formed at the front end and the inner end (left end) of the right first water jacket 36B in the vehicle width direction. A cooling water discharge passage 33g for supplying the cooling water discharged from the second battery case 32 to the right end of the right first water jacket 36B is formed downward on the side wall 33f.

  Returning to FIG. 2, two battery modules 37 are mounted on the upper surfaces of the left case bottom wall 33b and the right case bottom wall 33c of the first case main body 33, respectively. The rectangular parallelepiped battery module 37 is formed by stacking a plurality of battery cells 38 in the longitudinal direction, and is arranged in the front-rear direction so that the longitudinal direction (stacking direction) is along the left and right sides of the concave portion 33 a of the first case body 33. .

  A junction board 39 and a battery control device 40 are arranged on the rear upper surface of the concave portion 33a of the first case main body 33, and the upper surfaces of the left and right battery modules 37 of the junction board 39 and the battery control device 40 respectively have a cell voltage. A sensor 41 is provided.

  On a first cover 34 that covers an upper surface opening of the first case main body 33, a case upper wall 34a that forms a bottom wall of a second water jacket 47 described later is formed so as to extend in the vehicle width direction. At both ends in the vehicle width direction, left and right communication holes 34b and 34c communicating with the left and right cooling water supply passages 33e and the cooling water discharge passage 33g of the first case body 33 are formed. A raised portion 34d that covers the upper part of the junction board 39 and the battery control device 40 is formed at the center of the rear portion of the first cover 34 in the vehicle width direction, and on both sides of the raised portion 34e, above the left and right cell voltage sensors 41. Are formed to respectively cover the protrusions 34e. Further, a beam portion 34f, which has a trapezoidal cross section and protrudes upward, is formed in the vehicle width direction at a central portion in the front-rear direction of the first cover 34.

  The second battery case 32 includes a second case main body 42 and a second cover 43, both of which are made of metal die-cast, in which two left and right battery modules 45 in which battery cells 44 are stacked in the vehicle width direction are arranged. The cell voltage sensor 46 is disposed on the upper surface of each battery module 45. The case lower wall 42a of the second case body 42 of the second battery case 32 is provided with a concave portion 42b which is depressed upward, and the lower surface of the concave portion 42b and the case upper wall 34a of the first cover 34 of the first battery case 31 are formed. A second water jacket 47 (see FIGS. 3, 4, 6, and 7) is defined between the upper surface and the upper surface.

  As shown in the enlarged frames of FIGS. 2 and 3, the outer circumferences of the second water jacket 47 and the left and right communication holes 34 b and 34 c are on the lower surface of the case lower wall 42 a of the second case body 42 and on the case of the first cover 34. It is sealed by a seal member 48 sandwiched between the upper surfaces of the walls 34a. Outside the seal member 48, the upper surface of the case upper wall 34a of the first cover 34 is inclined downward toward the outside.

  As shown in FIG. 3, the front-rear section of the second cover 43 includes a case front wall 43a, a case upper wall 43b, and a case rear wall 43c, and the case rear wall 43c is inclined from upper front to lower rear. I do. A space having a triangular cross section is formed between the rear surface of the battery module 45 housed in the second battery case 32 and the case rear wall 43c, and the wirings 49 are housed in this space. A U-shaped cross-section beam 43d that opens upward is formed along the rear end of the case rear wall 43c of the second cover 43 in the vehicle width direction.

  As shown in FIG. 1, the battery pack 17 configured as described above is mounted on the lower surface of the floor panel 14 below the rear seat 16. The seat cushion 16a of the rear seat 16 is formed so as to rise forward, the front of the seat cushion 16a is disposed above the second battery case 32 of the battery pack 17, and the rear of the seat cushion 16a is connected to the first of the battery pack 17. It is arranged above the rear part of the battery case 31.

  Next, the operation of the embodiment of the present invention having the above configuration will be described.

  A muffler 19 provided on an exhaust pipe 18 extending rearward from the engine 12 mounted on the front part of the vehicle body is provided between the left case bottom wall 33b and the right case bottom wall 33c of the first case body 33 of the lower first battery case 31. Since the battery pack 17 is accommodated in the concave portion 33a extending in the front-rear direction, the battery pack 17 can be disposed at a position as low as possible while avoiding interference with the muffler 19, and thereby, the rear portion disposed above the battery pack 17 By arranging the seat 16 at a low position, the space above the occupant can be secured.

  The four battery modules 37 accommodated in the first battery case 31 are disposed with their longitudinal directions directed in the front-rear direction along the left and right sides of the concave portion 33a protruding upward from the center of the first case main body 33 in the vehicle width direction. Therefore, the mounting position of the battery module 37 can be lowered, and the height of the first cover 34 of the first battery case 31 can be kept low. On the other hand, the two battery modules 37 of the second battery case 32 are disposed on the second case body 42 with the longitudinal direction facing the vehicle width direction. It can be overlaid only on the front part of the battery case 31. As a result, the upper surface of the battery pack 17 has a stepped shape rising forward, and the seat cushion 16a of the rear seat 16 is arranged along the inclination of the rising front, so that the rear seat 16 is arranged at a lower position. The space above the occupant can be secured.

  In particular, the junction board 39 and the battery control device 40 of the battery pack 17 are arranged using the space above the concave portion 33a at the rear of the first battery case 31, and the cell voltage sensor 41 is connected to the battery module at the rear of the first battery case 31. Since the junction board 39 and the battery control device 40, which are relatively large in the vertical direction, are located in the space above the concave portion 33a in which the battery module 37 does not exist, the space is arranged using the space above the 37. By arranging the small-sized cell voltage sensor 41 in the space above the battery module 37, the height of the upper surface of the first battery case 31 can be reduced.

  As described above, since the junction board 39, the battery control device 40, and the cell voltage sensor 41 are accommodated, even if the height of the rear upper surface of the first battery case 31 is slightly increased, the rear upper surface of the first battery case 31 is increased. Is lower than the height of the upper surface of the second battery case 32, there is no possibility that the first battery case 31 will interfere with the seat cushion 16a of the rear seat 16.

  The case rear wall 43c of the second cover 43 of the second battery case 32 is inclined from the upper front to the lower rear, and the rear surface of the battery module 45 disposed at the front of the second battery case 32 and the rear wall of the case Since the wirings 49 are arranged in a space defined between the front surface of the rear seat 43c and the case 49, the space inside the second battery case 32 is reduced while avoiding the case rear wall 43c from interfering with the seat cushion 16a of the rear seat 16. Thus, the wirings 49 can be arranged using the space.

  Further, the first cover 34 of the first battery case 31 has a beam portion 34f extending in the vehicle width direction, and the second cover 43 of the second battery case 32 has a beam portion 43d extending in the vehicle width direction. The first battery case 31 and the second battery case 32 can be reinforced by the portions 34f and 43d to enhance the side impact resistance.

  Now, the low-temperature cooling water is supplied to the cooling water supply port 36a → the left first water jacket 36A → the cooling water supply passage 33e → the second water jacket 47 → the cooling water discharge passage 33g → the right first water jacket 36B → the cooling water discharge port 36b. And the four battery modules 37 are cooled by the first left water jacket 36A and the first right water jacket 36B formed at the bottom of the first battery case 31, and are formed at the bottom of the second battery case 32. The two battery modules 45 are cooled by the second water jacket 47 thus obtained.

  Since the bottom wall of the first case main body 33 of the first battery case 31 is separated into a left case bottom wall 33b and a right case bottom wall 33c by a concave portion 33a for accommodating the muffler 19, the water jacket of the first case main body 33 has a left side. The first water jacket 36A and the right first water jacket 36B are divided into two, and the lower surface of the second case body 42 of the second battery case 32 is separated from the left first water jacket 36A and the right first water jacket 36B. A two-water jacket 47 is provided.

  As described above, the battery pack 17 includes the three left first water jackets 36A, the right first water jacket 36B, and the second water jacket 47 divided into upper and lower parts and left and right parts. Since the cooling water supply passage 33e provided in the case side wall 33d and the cooling water discharge passage 33g provided in the right case side wall 33f are connected in series, the length of the cooling water passage is shortened and the number of parts is minimized to increase the number of parts. Cooling performance can be obtained.

  Further, the cooling water supply port 36a of the left first water jacket 36A and the cooling water discharge port 36b of the right first water jacket 36B are both provided on the front side of the first battery case 31, so that they are disposed in front of the battery pack 17. The length of the cooling water passage connecting the cooling water tank and the battery pack 17 can be minimized. Moreover, the cooling water supply port 36a and the cooling water supply passage 33e are provided at both ends in the vehicle width direction of the left first water jacket 36A, and the cooling water discharge port 36b and the cooling water discharge passage 33g are provided in the vehicle width direction of the right first water jacket 36B. Since the cooling water supply passage 33e and the cooling water discharge passage 33g are provided at both ends in the vehicle width direction of the second water jacket 47, the left first water jacket 36A, Cooling water can be evenly circulated in the internal space of the first right water jacket 36B and the second water jacket 47 to improve the cooling performance.

  In particular, a concave portion 42b that is depressed upward is formed in the case lower wall 42a of the second case main body 42 of the second battery case 32, and the battery module 45 is mounted on the upper surface of the concave portion 42b. The second water jacket 47 is formed between the first battery case 31 and the upper surface of the case upper wall 34a of the first cover 34 of the first battery case 31, so that the existing first battery can be used without adding any special member. The second water jacket 47 can be configured using the case upper wall 34a of the case 31 and the case lower wall 42a of the second battery case 32 as they are. Moreover, since the second water jacket 47 is partitioned outside the first battery case 31 and the second battery case 32, even if the cooling water leaks from the second water jacket 47, the cooling water is There is no danger of entering the inside of the first battery case 31 or the second battery case 32.

  Further, a cooling water supply passage 33e for connecting the left first water jacket 36A and the second water jacket 47 is formed in the left case side wall 33d of the first battery case 31, and the right first side wall 33f of the first battery case 31 is formed in the right case side wall 33f. Since the cooling water discharge passage 33g connecting the water jacket 36B and the second water jacket 47 is formed, a special member such as an external pipe is not required, so that not only the number of parts is reduced, but also the second water jacket 47 is formed. By surrounding the communication hole 34b and the communication hole 34b with the common seal member 48, the number of parts can be further reduced. Moreover, since the case upper wall 34a of the first cover 34 of the first battery case 31 is inclined outward and downward outside the seal member 48 that defines the outer periphery of the second water jacket 47 (see FIG. 3), Even if the cooling water leaks from the seal member 48, the leaking cooling water is prevented from collecting on the upper surface of the case upper wall 34a of the first cover 34.

  Further, the battery module 45 accommodated in the second battery case 32 has the battery cells 44 stacked in the vehicle width direction. Can be avoided. At this time, the second water jacket 47 of the second battery case 32 is arranged so that the cooling water flows in the vehicle width direction, so that all the battery cells 44 of the battery module 45 can be efficiently cooled.

Second embodiment

  Next, a second embodiment of the present invention will be described with reference to FIG.

  The battery pack 17 according to the first embodiment includes a lower first battery case 31 and an upper second battery case 32. The battery pack 17 according to the second embodiment includes a second battery case. The third battery case 51 further includes one or more third battery cases 51 stacked on the second battery case 32. The third battery case 51 includes a lower third case body 52 and an upper third cover 53. The third battery case 51 includes a second cover 43 of the second battery case 32 and a third case of the upper third battery case 51. A third water jacket 54 is formed between the main body 52 or between the third cover 53 of the lower third battery case 51 and the third case main body 52 of the upper third battery case 51. .

  A cooling water supply passage 42e and a cooling water discharge passage 42f are formed in the left case side wall 42c and the right case side wall 42d of the second case body 42 of the second battery case 32, respectively. A cooling water supply passage 52c and a cooling water discharge passage 52d communicating with the cooling water supply passage 42e and the cooling water discharge passage 42f of the second case body 42 are formed on the left case side wall 52a and the right case side wall 52b of the case body 52, respectively. Is done.

  The cooling water supply passage 33e and the cooling water discharge passage 33g of the first case body 33, the cooling water supply passage 42e and the cooling water discharge passage 42f of the second case body 42, the cooling water supply passage 52c of the third case body 52, and The cooling water discharge passage 52d is configured such that the cross-sectional area of the flow passage gradually increases from the lower one to the upper one, and the left and right first water jackets 36A, 36B of the first battery case 31 and the second one of the second battery case 32. The volumes of the second water jacket 47 and the third water jacket 54 of the third battery case 51 gradually increase from the lower one to the upper one.

  According to the second embodiment having the above-described configuration, the third water jacket 54 of the third battery case 51 is connected in parallel to the second water jacket 47 of the second battery case 32. Even in the case where the cooling water passages are superimposed on each other, the cooling water can be efficiently supplied to the third water jacket 54 of the third battery case 51 without complicating the structure of the cooling water passage.

  In addition, since the upper-stage battery case has a larger flow path cross-sectional area of the cooling water supply passage and the cooling water discharge passage, by increasing the supply amount of the cooling water to the upper cooling water jacket where the cooling water is difficult to reach, The cooling effect of the battery case in each stage can be made uniform. Furthermore, since the capacity of the cooling water jacket is larger in the upper battery case, the cooling water supply amount to the upper cooling water jacket in which the cooling water is difficult to reach is increased, thereby reducing the cooling effect of the battery case in each stage. It can be made uniform.

  The embodiments of the present invention have been described above. However, various design changes can be made in the present invention without departing from the gist thereof.

  For example, the invention of claim 1 is not limited to the one including only the first battery case 31 and the second battery case 32, but includes the third battery case 51 in addition to the first battery case 31 and the second battery case 32. Also includes things.

  The refrigerant of the present invention is not limited to the cooling water of the embodiment.

17 Battery Pack 31 First Battery Case 32 Second Battery Case 33d Left Case Side Wall (Case Side Wall)
33e cooling water supply passage (refrigerant supply passage)
33f right case side wall (case side wall)
33g cooling water discharge passage (refrigerant discharge passage)
34a Case upper wall 42a Case lower wall 42b Recess 42e Cooling water supply passage (refrigerant supply passage)
42f cooling water discharge passage (refrigerant discharge passage)
45 Battery module (battery)
47 2nd water jacket (refrigerant jacket)
48 sealing member 52 third battery case 52a left case side wall (case side wall)
52b Right case side wall (case side wall)
52c Cooling water supply passage (refrigerant supply passage)
52d cooling water discharge passage (refrigerant discharge passage)
54 3rd water jacket (other refrigerant jacket)

Claims (6)

A battery pack (17) in which a second battery case (32) is superimposed on a first battery case (31) is provided, and a coolant jacket (47) through which a coolant flows is formed on a lower surface of the second battery case (32). Battery pack cooling structure,
The case lower wall (42a) of the second battery case (32) is formed with a concave portion (42b) that is depressed upward, and a battery (45) is placed on the upper surface of the concave portion (42b). The cooling structure for a battery pack, wherein the refrigerant jacket (47) is formed between the lower surface of the first battery case (31) and the upper surface of the first battery case (31) connected thereto.   A coolant supply passage (33e) for supplying a coolant to the coolant jacket (47) and a coolant for discharging the coolant from the coolant jacket (47) are provided on case side walls (33d, 33f) of the first battery case (31). The cooling structure for a battery pack according to claim 1, wherein a discharge passage (33g) is formed.   The case upper wall (34a) of the first battery case (31) is inclined downward and outward outside the seal member (48) surrounding the outer periphery of the refrigerant jacket (47). The cooling structure for a battery pack according to claim 1 or 2.   One or a plurality of third battery cases (51) are superimposed on the upper side of the second battery case (32), and the lower surface of the third battery case (51) has a battery case ( Another coolant jacket (54) is formed between the battery case (32, 51) and the case side wall (52a, 52b) of the third battery case (51). ), A refrigerant supply passage (52c) and a refrigerant discharge passage (52d) communicating with the refrigerant supply passages (42e, 52c) and the refrigerant discharge passages (42f, 52d), respectively, are formed. A battery pack cooling structure as described in the above.   The flow path cross-sectional area of the refrigerant supply passages (33e, 42e, 52c) and the refrigerant discharge passages (33g, 42f, 52d) is larger in the upper battery case (32, 51). 4. The cooling structure for a battery pack according to claim 1.   The cooling structure for a battery pack according to claim 4, wherein the capacity of the refrigerant jacket (47, 54) is larger in the upper battery case (32, 51).

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